// Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#pragma once

#include <variant>
#include "paddle/common/overloaded.h"

namespace common {

template <typename T>
struct AdtTypeId {
  using type = T;
};

template <typename... Ts>
struct AdtBaseTypeId : public std::variant<AdtTypeId<Ts>...> {
  using std::variant<AdtTypeId<Ts>...>::variant;

  const std::variant<AdtTypeId<Ts>...>& variant() const {
    return static_cast<const std::variant<AdtTypeId<Ts>...>&>(*this);
  }

  template <typename... Args>
  decltype(auto) Match(Args&&... args) const {
    return std::visit(Overloaded{std::forward<Args>(args)...}, variant());
  }
};

}  // namespace common
